Many communication protocols specify multiple communication layers. For example, the various cellular communication protocols specified by the Third Generation Partnership Project (3GPP) use a hierarchical structure comprising a physical layer (also referred to as PHY or Layer-1—L1), Layer-2 (L2), a Radio Resource Control (RRC) layer and a Non-Access stratum (NAS) layer.
Among other tasks, the various layers transfer control-plane or signaling messages. In Universal Mobile Telecommunications System (UMTS) networks, for example, control-plane messages are transferred as Radio Link Control Service Data Units (RLC SDUs), as specified, for example, in “Technical Specification Group Radio Access Network; Radio Link Control (RLC) protocol specification (Release 11),” TS 25.322, version 11.0.0, September, 2012, which is incorporated herein by reference.
In Evolved Universal Terrestrial Radio Access (E-UTRA) networks, also referred to as Long Term Evolution (LTE) or LTE-Advanced (LTE-A), control-plane messages are transferred as Packet Data Convergence Protocol (PDCP) SDUs, as specified, for example, in “Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data Convergence Protocol (PDCP) specification (Release 11),” TS 36.323, version 11.0.0, September, 2012, which is incorporated herein by reference.
The description above is presented as a general overview of related art in this field and should not be construed as an admission that any of the information it contains constitutes prior art against the present patent application.